The present invention relates generally to the field of input devices. More particularly, the present invention relates to any human-machine interface for operating devices that use keys.
The popularity and use of personal computers (PCs), digital assistants (PDAs), wireless telephones, extended function pagers and other compact computing devices has increased in recent years. A typical PDA or hand-held computer is primarily a lightweight, compact communication tool that can typically be held in one hand, leaving the other free to input data with a pen type stylus on a touch sensitive screen or keyboard. The keyboard may be integrated into the device or attached externally. Many wireless telephones and pagers have expanded capabilities beyond the original intended use to include storing and retrieving numbers, messages, emails, and accessing the Internet.
Many compact and portable computing devices use an abbreviated and/or compact keyboard to input data and select functions. In the case of PDAs, the keyboard is generally several times the size of the PDAs, attaches externally, and offers similar functionality to that of a standard PC keyboard. A key is typically labeled with a primary function (i.e., the numeric character xe2x80x9c1xe2x80x9d) and a secondary function (i.e., the character xe2x80x9c!xe2x80x9d). To access the secondary function a user must change the mode for the keyboard such as by holding down a shift or control key while depressing the key corresponding to the secondary function. Additionally, most keyboards include a shift lock that locks the keyboard in the secondary function mode. Often, a keyboard has a single lighted (i.e., LED) indicator showing the current mode of the keyboard, for example, a xe2x80x9cCaps Lockxe2x80x9d indicator. Some compact computing devices can indicate the keyboard""s current mode on the device""s display.
A problem arises when a compact computing device requires substantially all of the functions of a full size PC keyboard but has a limited area for keys. One approach to include substantially all of the functions of a full size PC keyboard is to require a single key to have four or more functions (i.e., four or more functional modes). Unfortunately, providing four or more functional modes requires some method of selecting and indicating the mode to the user. One indicating method requires the user to search for a function indicator on the keyboard and/or on the display to accurately determine the current mode of the keyboard to ensure accurate data entry.
Another approach is to use a virtual keyboard. A virtual keyboard is a graphical representation of a typical full-size PC keyboard, or a portion thereof, that when touched inputs the corresponding character into a portion of the display area. The user can also select other virtual keyboards (i.e., other portions of a typical full-size keyboard) such as a numeric or symbol keypad. The virtual keyboard approach consumes a large portion of an already limited display area with the virtual keys and thus limits the user""s ability to view and edit entered text.
In one embodiment a light source is provided to illuminate one or more keys. Each key has at least one glyph. The color of each glyph corresponds to the light source.